Williamwhitmania taraxaci gen. nov., sp. nov., a proteolytic anaerobe with a novel type of cytology from Lake Untersee in Antarctica, description of Williamwhitmaniaceae fam. nov., and emendation of the order Bacteroidales Krieg 2012.

The proteolytic bacterium strain A7P-90m was isolated from Lake Untersee, Antarctica. The anoxic water was collected from a perennially sealed (~100 millennia) glacial ice lake. Gram-stain-negative cells were 0.

Sanguibacter gelidistatuariae sp. nov., a novel psychrotolerant anaerobe from an ice sculpture in Antarctica, and emendation of descriptions of the family Sanguibacteraceae, the genus Sanguibacter and species S. antarcticus, S. inulinus, S. kedieii, S. marinus, S. soli and S. suarezii.

A novel psychrotolerant bacterium, strain ISLP-3T, was isolated from a sample of naturally formed ice sculpture on the shore of Lake Podprudnoye in Antarctica. Cells were motile, stained Gram-positive, non-spore-forming, straight or slightly curved rods with the shape of a baseball bat. The new isolate was facultatively anaerobic and catalase-positive.

Raineyella antarctica gen. nov., sp. nov., a psychrotolerant, d-amino-acid-utilizing anaerobe isolated from two geographic locations of the Southern Hemisphere.

A Gram-stain-positive bacterium, strain LZ-22T, was isolated from a rhizosphere of moss Leptobryum sp. collected at the shore of Lake Zub in Antarctica. Cells were motile, straight or pleomorphic rods with sizes of 0.

The antiproliferative function of violacein-like purple violet pigment (PVP) from an Antarctic Janthinobacterium sp. Ant5-2 in UV-induced 2237 fibrosarcoma.

Background: In this study, we have investigated the chemotherapeutic potential of a purple violet pigment (PVP), which was isolated from a previously undescribed Antarctic Janthinobacterium sp. (Ant5-2), against murine UV-induced 2237 fibrosarcoma and B16F10 melanoma cells.

Methods: The 2237, B16F10, C50, and NIH3T3 cells were treated with PVP at different doses and for different times, and their proliferation and viability were detected by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay.

Proteocatella sphenisci gen. nov., sp. nov., a psychrotolerant, spore-forming anaerobe isolated from penguin guano.

A novel, obligately anaerobic, psychrotolerant bacterium, designated strain PPP2T, was isolated from guano of the Magellanic penguin (Spheniscus magellanicus) in Chilean Patagonia. Cells were Gram-stain-positive, spore-forming, straight rods (0.7-0.

Spirochaeta dissipatitropha sp. nov., an alkaliphilic, obligately anaerobic bacterium, and emended description of the genus Spirochaeta Ehrenberg 1835.

A novel obligately anaerobic, mesophilic, alkaliphilic spirochaete, strain ASpC2(T), was isolated from an anaerobic sediment of alkaline, hypersaline Owens Lake in California, USA. The Gram-negative cells are motile, helical in shape and 0.23 x 8.

Microbial extremophiles at the limits of life.

Prokaryotic extremophiles were the first representatives of life on Earth and they are responsible for the genesis of geological structures during the evolution and creation of all currently known ecosystems. Flexibility of the genome probably allowed life to adapt to a wide spectrum of extreme environments. As a result, modern prokaryotic diversity formed in a framework of physico-chemical factors, and it is composed of: thermophilic, psychrophilic, acidophilic, alkaliphilic, halophilic, barophilic, and radioresistant species.

Thermococcus thioreducens sp. nov., a novel hyperthermophilic, obligately sulfur-reducing archaeon from a deep-sea hydrothermal vent.

A hyperthermophilic, sulfur-reducing, organo-heterotrophic archaeon, strain OGL-20P(T), was isolated from 'black smoker' chimney material from the Rainbow hydrothermal vent site on the Mid-Atlantic Ridge (36.2 degrees N, 33.9 degrees W).

Anaerovirgula multivorans gen. nov., sp. nov., a novel spore-forming, alkaliphilic anaerobe isolated from Owens Lake, California, USA.

A novel, alkaliphilic, obligately anaerobic bacterium, strain SCAT, was isolated from mud sediments of a soda lake in California, USA. The rod-shaped cells were motile, Gram-positive, formed spores and were 0.4-0.

Trichococcus patagoniensis sp. nov., a facultative anaerobe that grows at -5 degrees C, isolated from penguin guano in Chilean Patagonia.

A novel, extremely psychrotolerant, facultative anaerobe, strain PmagG1(T), was isolated from guano of Magellanic penguins (Spheniscus magellanicus) collected in Chilean Patagonia. Gram-variable, motile cocci with a diameter of 1.3-2.

Carnobacterium pleistocenium sp. nov., a novel psychrotolerant, facultative anaerobe isolated from permafrost of the Fox Tunnel in Alaska.

A novel, psychrotolerant, facultative anaerobe, strain FTR1T, was isolated from Pleistocene ice from the permafrost tunnel in Fox, Alaska. Gram-positive, motile, rod-shaped cells were observed with sizes 0.6-0.

Desulfonatronum thiodismutans sp. nov., a novel alkaliphilic, sulfate-reducing bacterium capable of lithoautotrophic growth.

A novel alkaliphilic, sulfate-reducing bacterium, strain MLF1(T), was isolated from sediments of soda Mono Lake, California. Gram-negative vibrio-shaped cells were observed, which were 0.6-0.

Spirochaeta americana sp. nov., a new haloalkaliphilic, obligately anaerobic spirochaete isolated from soda Mono Lake in California.

A novel, obligately anaerobic, mesophilic, haloalkaliphilic spirochaete, strain ASpG1(T), was isolated from sediments of the alkaline, hypersaline Mono Lake in California, USA. Cells of the Gram-negative strain were motile and spirochaete-shaped with sizes of 0.2-0.

Tindallia californiensis sp. nov., a new anaerobic, haloalkaliphilic, spore-forming acetogen isolated from Mono Lake in California.

A novel extremely haloalkaliphilic, strictly anaerobic, acetogenic bacterium strain APO was isolated from sediments of the athalassic, meromictic, alkaline Mono Lake in California. The Gram-positive, spore-forming, slightly curved rods with sizes 0.55-0.